Preheat your oven to 400°F (200°C).
In a small oven-safe skillet or baking dish, mix the rinsed quinoa with 3/4 cup water or broth. Stir in the 1/2 cup canned tomatoes (with a bit of their juice), cumin, smoked paprika (if using), salt, and pepper.
Spread the diced zucchini and onion evenly over the quinoa-tomato mixture. The veggies will roast while the quinoa cooks below, absorbing the tomato flavor.
Cover tightly with foil (or a lid) and bake for 25-30 minutes. Check at 25 minutes—quinoa should be fluffy and liquid absorbed. If it’s too wet, uncover and bake 5 more minutes.
Remove from the oven, fluff with a fork to combine the roasted veggies and quinoa, and sprinkle with fresh parsley. Add a squeeze of lemon juice if desired.
Split between two plates and serve warm.